Investigation of La-doped 0.25Pb(ZnNb)O-0.75Pb(ZrTi)O ceramics near morphotropic phase boundary

La-doped 0.25Pb(ZnNb)O-0.75Pb(ZrTi)O (x = 0.51–0.57) ceramics were prepared by a conventional mixed oxide method. The piezoelectric and dielectric properties of various compositions near the morphotropic phase boundary (MPB) were investigated. The MPB was determined by X-ray diffraction (XRD) patterns. The optimal properties were obtained in the specimen with Zr/Ti = 53/47: d = 570 pC/N, k = 0.60, ε = 3900, tgδ = 1.9%, T = 204°C, P = 35.21 μC/cm, E = 11.62 kV/cm, which means it is a good candidate for applications.